"He's just an ordinary man when we meet him," exec Andrew Kreisberg said in a conference call. "Part of the fun for the audience [is] the ride and to see how we do our Arrow take on the Flash legacy."

The introduction of the Flash will signal the introduction of more "insane concepts" to the Arrow world, added DC's Geoff Johns, hinting at the introduction of more super-powered characters.

"These powers won't be treated as commonplace," Kreisberg affirmed. "They will be extraordinary events, so the world and characters will react accordingly."

Kreisberg and Johns also revealed that it was fellow exec producer Greg Berlanti who first suggested a Flash TV spinoff.

"Despite the fact that he's got superpowers, there's something very relatable about Barry... of all the big seven of the Justice League," Kreisberg continued.

"He got his powers by accident, he isn't a god, he wasn't seeking this out, it came to him … His reactions to that feel very human and grounded.

"Oliver Queen (Stephen Amell) is a very dark and tortured soul, and Barry is not. I think it'll be a fun bi-play to see these two characters together - they both have distinctly different world views while caring deeply about right and wrong."

The Flash will appear in episodes eight, nine and 20 of Arrow's second season, which premieres on October 9 on The CW in the US and will air on Sky1 in the UK.